As technology for measuring a location of a mobile terminal, a method of using a Global Positioning System (GPS) and a method of using a receiving signal of a wireless network base station are generally used. However, the method of using GPS has a drawback that cannot be used indoor and the method of using a receiving signal of a base station has a drawback of somewhat deteriorated accuracy.
As the prior art of measuring a location of a terminal, there is technology disclosed at Korean Patent Laid-Open Publication Nos. 2013-0002748 (method of positioning location and system and apparatus for the same) and 2013-0002240 (positioning system for location-based service using wireless LAN signal intensity). However, because the conventional art has an error range of about several meters when measuring a location of a mobile terminal, the conventional art has a drawback that accurate positioning to distinguish a location of each terminal located at a near distance is impossible. Therefore, conventional positioning technology has a problem that cannot provide a service in which a user of a mobile terminal specifies a random terminal located within several meters and transmits a message to a user of the specified terminal.